Rhododendron plant named ‘NCRX2’

ABSTRACT

A new and distinct cultivar of  Rhododendron  plant named ‘NCRX2’ is disclosed, characterized by profuse pink/lavender flowers. Plants have a compact habit, and dark purple winter foliage. The new cultivar is a  Rhododendron , suitable for ornamental garden purposes.

Latin name of the genus and species: Rhododendron hybrida.

Variety denomination: ‘NCRX2’.

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct triploid hybrid Rhododendron cultivar hereinafter referred to by the cultivar name ‘NCRX2’. Developed by a breeding program in Mills River, N.C., ‘NCRX2’ was selected for a prolific floral display of pink-lavender flowers, compact form, reduced fertility, and showy, dark purple, winter foliage color. ‘NCRX2’ was selected from a population of sister plants derived from controlled, hand pollinations between the seed parent, Rhododendron ‘Elite’ (unpatented) and pollen parent, Rhododendron ‘Bubblegum’ (unpatented), in 2007.

The first asexual propagation of ‘NCRX2’ occurred in June 2009 by firm softwood cuttings at a research nursery in Mills River, N.C. ‘NCRX2’ roots readily from firm softwood cuttings treated with a basal dip of 5,000 ppm indole butyric acid (potassium salt) in water. ‘NCRX2’ has been found to retain its distinctive characteristics through successive asexual propagations over the course of 9 years.

SUMMARY OF THE INVENTION

The following are the unique combination of characteristics of this new cultivar when grown under standard horticultural practices at Mills River, N.C.

-   -   1. Profuse flowering with bright pink-lavender flowers.     -   2. Dark purple winter foliage.     -   3. Triploid cytotype.     -   4. Compact habit.

COMPARISON TO PARENT VARIETIES

‘NCRX2’ is similar in most horticultural characteristics to the seed parent. Plants of the new cultivar ‘NCRX2’ however differ in the following:

-   -   1. The new variety has pink/lavender flowers, while the seed         parent has lavender/purple flowers.     -   2. The new variety is compact, while the seed parent is larger,         less compact.

‘NCRX2’ is similar in most horticultural characteristics to the pollen parent. Plants of the new cultivar ‘NCRX2’ however differ in the following:

-   -   1. The new variety has pink/lavender flowers, while the pollen         parent has brighter pink flowers.     -   2. The new variety is compact, while the pollen parent is         larger, less compact.

COMMERCIAL COMPARISON

‘NCRX2’ can be compared to the commercial variety Rhododendron ‘Amy Cotta’, U.S. Plant Pat. No. 11,311. Plants of the new cultivar ‘NCRX2’ are similar to plants of ‘Amy Cotta’ in most horticultural characteristics. Plants of the new cultivar ‘NCRX2’, however, differ in the following:

-   -   1. The new variety has pink/lavender flowers, while this         comparator has more purple flowers.     -   2. The new variety has dark purple Winter foliage, while this         comparator has green Winter foliage.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

‘NCRX2’ is illustrated by the accompanying photographs which show the plant's form, foliage, and inflorescences. The colors shown are as true as can be reasonably obtained by conventional photographic procedures. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description, which accurately describe the colors of the new hybrid Rhododendron.

FIG. 1 shows the form and flowers of 4-year-old plant of ‘NCRX2’ growing in Arden, N.C. on Mar. 31, 2018.

FIG. 2 shows the foliage and flowers of 4-year-old plant of ‘NCRX2’ growing in Arden, N.C. on Mar. 31, 2018.

FIG. 3 shows a close up view of individual flowers of 4-year-old plant of ‘NCRX2’ growing in Arden, N.C. on Mar. 31, 2018.

FIG. 4 shows the winter foliage color from 4-year-old plant of ‘NCRX2’ growing in Mills River, N.C. on Jan. 15, 2018.

DETAILED BOTANICAL DESCRIPTION

The following is a detailed description of the botanical characteristics of the new and distinct hybrid rhododendron known by the denomination ‘NCRX2’. The detailed description was taken of 4-year-old plants growing Mills River, N.C. For each measurable character, ten random measurements were recorded and used to derive averages and characteristic ranges. All colors cited herein refer to The Royal Horticultural Society Colour Chart (R.H.S.), 2015 Edition. Where specific dimensions, sizes, colors, and other characteristics are described, it is to be understood that these descriptions are approximations for variable characters that are labile and may change as a result of environment and growing conditions.

-   Botanical classification: Rhododendron hybrida ‘NCRX2’. -   Propagation: Typically by firm softwood cuttings.

PLANT

-   Plant type: Broad-leaf evergreen shrub. -   Growth habit: Well-branched, rounded. -   Height: 1 m. -   Width: 1 m. -   Growth rate: Moderate. -   Roots: Fibrous. -   Shoots (new growth):     -   -   Shape.—Rounded.         -   Color.—RHS Yellow-Green 144C which fades to Yellow-Green             144D at tips.         -   Texture.—Glandular; older growth sees a reduction in visible             glands.         -   Pubescence.—Glabrous.         -   Shoot diameter.—Average 2.2 mm.         -   Shoot length.—Average 7.2 cm.         -   Stem aspect.—Stems are held upright, often at a 45° angle             from the branch. -   Shoots (mature growth):     -   -   Shape.—Rounded.         -   Color.—Predominantly RHS Greyed-Orange 165B.         -   Texture.—Smooth.         -   Pubescence.—None.         -   Length.—Average 17.1 cm.         -   Diameter.—Average 2.0 mm. -   Branching (mature growth):     -   -   Shape.—Rounded.         -   Color.—Between RHS Greyed-Orange 164B and 166A.         -   Texture.—Smooth.         -   Pubescence.—None.         -   Branch diameter.—Average 5.0 mm.         -   Branch length.—Average 28.6 cm.         -   Branching.—Generally branches at terminal flowering points;             branches arch upwards.         -   Branch aspect.—Lower branches are held at approximately 90°             angles; upper branches decrease in angle to approximately             45°. -   Trunk (at soil line):     -   -   Shape.—Round.         -   Color.—Mix of RHS Grey-Brown N200B and RHS Greyed-Orange             177D. Exposed epidermis visible through exfoliation is often             near Greyed-Orange 177D.         -   Texture.—Exfoliates.         -   Pubescence.—None. -   Age of plant described: Approximately 4 years.

FOLIAGE

-   Leaf:     -   -   Type.—Simple, lepidote.         -   Arrangement.—Alternate.         -   Persistence.—Evergreen to semi-evergreen.         -   Division.—Entire.         -   Shape.—Elliptic; occasionally ovate.         -   Orientation.—Leaves are held approximately 45°-90° from the             stem.         -   Aspect.—Leaves are held flat, parallel to the ground.         -   Apex.—Broadly acute; occasionally rounded or broadly             acuminate, especially emerging leaves.         -   Base.—Cuneate.         -   Margin.—Entire.         -   Venation.—Reticulate.         -   Color.—Immature leaf, upper surface: Mix of RHS Yellow-Green             143A and Yellow-Green 144A.         -   Surface.—Glabrous. Immature leaf lower surface: RHS Green             138B to Yellow-Green 145B.         -   Surface.—Highly glandular. -   Mature leaf:     -   -   Length.—Average 6.6 cm.         -   Width.—Average 3.5 cm.         -   Summer color.—Upper surface: Near RHS Green NN137A.         -   Surface.—Glabrous. Lower surface: Between RHS Yellow-Green             148A and 148B.         -   Surface.—Glandular.         -   Fall/winter color.—Upper surface: Variable, ranging from RHS             Green NN137A, to Greyed-Purple N186C, 187A, 187B and 185A in             some instances deepening into 186A. Lower surface: RHS             Yellow-Green 152A. -   Petiole:     -   -   Shape.—Rounded with a flattened adaxial side.         -   Length.—Average 10 mm.         -   Diameter.—Average 1.3 mm.         -   Texture.—Pubescent.         -   Color.—Near RHS Greyed-Orange 177A.

FLOWER

-   Inflorescence:     -   -   Type.—Congested terminal raceme (truss).         -   Fragrance.—Very slight.         -   Inflorescence/truss measurements at anthesis.—Length:             Average 7.5 cm. Width: Average 10.8 cm.         -   Flowering season.—Early to Mid-April (in Zone 6B).         -   Flower number and consistency.—Plants flower each year             consistently. Inflorescences are typically present on most             primary terminal shoots.         -   Flowers per inflorescence.—Variable, ranging from 3-12;             lower branches often have fewer flowers.         -   Longevity of flowers.—Flowers persist for several weeks.         -   Self-cleaning or persistent.—Self-cleaning. -   Flowers:     -   -   Expanding buds.—Shape: Obovate to elliptic. Length: Average             31.0 mm. Diameter (at widest point): Average 9.9 mm. Color:             Varies between and includes RHS Red-Purple 72D and RHS             Purple N74B. Bud scales: Present.         -   Perianth (at anthesis).—Depth: Average 4.0 cm. Width (at             widest point): Average 4.9 cm. Height: Average 5.0 cm. Petal             number: 5. Aspect: Individual flowers are held at near 90°             angles at the base of the inflorescence; the angle             decreases, and flowers are held more upright (towards 45°             angles) along the peduncle towards the inflorescence apex.             Shape: Elliptical, rounded petals fuse approximately at the             halfway point and spread open resulting in a tubular,             trumpet-like corolla; edges are slightly ruffled.             Attachment: Pedicellate. -   Petals:     -   -   Length.—Average 3.8 cm.         -   Width.—Average 21.6 mm.         -   Petal shape.—Elliptic.         -   Apex.—Rounded.         -   Base.—Fused.         -   Margin.—Entire.         -   Fused or unfused.—Fused.         -   Color (at anthesis).—Upper surface: RHS Red-Purple N74D to             N74B. Surface: Glabrous. Blotch: RHS Red-Purple 71B and             Red-Purple N66B. Length: Average 1.5 cm. Width: Average             1.6 cm. Lower surface: RHS Red-Purple N74D to N74B. Surface:             Glabrous, with the presence of small white glands             approximately 0.25 mm in diameter. -   Calyx/receptacle:     -   -   Shape.—Lobed; sepals highly reduced.         -   Arrangement.—Whorled.         -   Diameter.—Average 3.8 mm.         -   Depth.—Average 2.19 mm.         -   Apex.—Broad acute.         -   Margin.—Entire.         -   Surface.—Glandular with fine, translucent pubescence at             petal union.         -   Sepal width.—Average 2.3 mm.         -   Sepal depth.—Average 1.7 mm. -   Peduncles:     -   -   Shape.—Rounded.         -   Length.—Average range about 3 to 5 cm from closest leaf.         -   Diameter.—Average 4 to 5 mm.         -   Color.—Near RHS Greyed-Orange 166B.         -   Surface.—Smooth. -   Pedicels:     -   -   Shape.—Rounded.         -   Length.—Average 11.3 mm.         -   Diameter.—Average 1.1 mm.         -   Color.—RHS Red 48B mixed with Yellow-Green 145C. 145C             coloration becomes more pronounced where the pedicel and             peduncle meet.         -   Surface.—Highly glandular.

REPRODUCTIVE ORGANS

-   Gynoecium:     -   -   Pistil number.—1.         -   Pistil length.—Average 3.7 cm.         -   Pistil diameter.—Average 1.4 mm.         -   Stigma shape.—Flattened; ovoid.         -   Stigma diameter.—Average 1.2 mm.         -   Style color.—RHS Red-Purple 59A.         -   Ovary diameter.—Average 2.2 mm.         -   Ovary length.—Average 4.1 mm.         -   Ovary color.—RHS Green 139C. -   Androecium:     -   -   Stamen number.—10.         -   Anther shape.—Ovoid with two apical pores.         -   Anther attachment.—Dorsifixed.         -   Anther length.—Average 2.0 mm.         -   Anther width.—Average 0.9 mm.         -   Anther color.—RHS Purple N77C.         -   Filament length.—Stamens are pentadynamous.         -   Long stamens.—Average 33.3 mm.         -   Short stamens.—Average 24.4 mm.         -   Filament diameter.—Average 0.4 mm.         -   Filament color.—Ranges between RHS Purple 75D and 75C, to             Red-Purple 69D at base. Filaments are pubescent at base.         -   Amount of pollen.—Present, but very little produced.         -   Pollen type.—Threadlike, vicinate.         -   Pollen color.—RHS Purple 75C to 75D.

OTHER CHARACTERISTICS

-   Disease and pest resistance: Not observed to be susceptible nor     resistant to normal diseases and pests of Rhododendron. -   Temperature tolerance: Has been reliably cold hardy in USDA 6A. -   Fruit/seed production: Not observed to date. 

What is claimed is:
 1. A new and distinct cultivar of Rhododendron plant named ‘NCRX2’ as herein illustrated and described. 